(1) Field of the Invention
A present invention relates to a robot apparatus and, more particularly, to a robot apparatus in which a robot movable section and a robot control section are adjacently disposed.
(2) Description of the Related Art
A conventional robot apparatus has a robot movable section and a robot controller which are separated from each other, and the robot movable section and the robot controller are electrically connected to each other via a coupling cable. Thus, the robot controller makes the robot movable section perform an arbitrary motion by giving a motion command to the robot movable section.
One method of connecting the robot movable section and the robot controller is by installing the robot controller at a place distant from the robot movable section and by connecting the robot movable section and the robot controller to each other via a long coupling cable. With this method, a space for installing the robot controller must be provided additionally. Further, a facility for protecting the coupling cable is needed. Therefore, the method of connecting the robot movable section with the robot controller, which is positioned apart therefrom, by using a long cable is disadvantageous in terms of effective use of limited space and facility.
To overcome this disadvantage, a method can be used in which the robot movable section and the robot controller are directly connected to each other by means of connectors which both of the robot movable section and the robot controller have, without the use of a cable. With this method, the robot controller is installed adjacent to the robot movable section in a dead space outside the work envelope of the robot movable section.
FIG. 6 shows a conventional robot apparatus. In this figure, a robot controller, contained in a housing 100a, is installed adjacent to a robot movable section 10a. The robot controller and the robot movable section 10a are electrically connected to each other via a connector 114aprovided on the housing 100a and a connector 12a provided on the back side of the robot movable section 10a.
The robot movable section 10a is fixed to the floor via a base 11a. On the base 11a, a J1 arm 17a is provided via a rotating mechanism portion. At the distal end of the J1 arm 17a, a J2 arm 13a is provided via the rotating mechanism portion. Further, at the distal end of the J2 arm 13a, a J3 arm 14a is provided via the rotating mechanism portion. The distal end of the J3 arm 14a constitutes a wrist portion 15a. Various types of hands can be attached to this wrist portion 15a. The central position of the wrist portion is called TCP (Tool Center Point). The TCP can move in a region inside a work envelope 20a. Hereinafter, "the work envelope of robot" refers to a range in which the TCP moves.
Thus, the housing 100a containing the robot controller is reduced in size so that it can be installed outside the range 20a in which the TCP moves, by which the robot controller can be installed close to the robot movable section. As an example of this configuration, the applicant has filed Japanese Patent Application No. 5-259635.
However, for the space to install the robot controller, a space in which both of the robot movable section and the robot controller can be installed must be secured. Therefore, a broad installation space is needed. Also, in order to increase the work envelope of the robot, the space occupied by the robot controller must be decreased.
Moreover, as the application of the robot apparatus is diversified, the decrease in the installation area for the robot apparatus and the expansion of the work envelope of the robot are demanded. For example, when a production line at a factory using robot apparatuses is laid out, the less the installation area for the robot apparatus is, the more freely work benches or the like can be arranged around the robot apparatus. Further, by expanding the work envelope of the robot, the space around the robot can be used effectively, by which the flexibility of the layout is increased. Therefore, a layout which brings about improved productivity can be achieved.